Q. 75.0( 2 Votes )

# How many terms of the sequence must be taken to make the sum ?

Answer :

Given:

Sum of GP = 39 + 13√3

∴ Common Ratio = r =

a = √3

To find: Number of terms = n.

Sum of GP for n terms =

⇒

⇒

⇒

⇒ 26√3 = √3(3^{n} - 1)

⇒ 27 = 3^{n}

⇒ n = 3.

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